net/systemeD/halcyon/NestedXMLLoader.as

   1 package net.systemeD.halcyon {
   2
   3         /** A class permitting you to load XML files containing 'include' elements (for example,
   4         *   <include file="cuisine.xml" />, which will be automatically replaced with the contents of the file.
   5         *
   6         *   Typical usage:
   7         *
   8         *               xmlLoader=new NestedXMLLoader();
   9         *               xmlLoader.addEventListener(Event.COMPLETE, onFeatureLoad);
  10         *               xmlLoader.load("root.xml");
  11         *
  12         *       onFeatureLoad can then access the XML via event.target.xml.
  13         */
  14
  15         import flash.events.*;
  16     import flash.net.URLLoader;
  17     import flash.net.URLRequest;
  18
  19         public class NestedXMLLoader extends EventDispatcher {
  20                 public var xml:XML = null;
  21                 private var url:String;
  22                 private var count:int;
  23
  24                 public function NestedXMLLoader() {
  25                 }
  26
  27                 public function load(url:String):void {
  28                         this.url=url;
  29                         var request:URLRequest=new URLRequest(url+"?d="+Math.random());
  30                         var loader:URLLoader = new URLLoader();
  31                         loader.addEventListener(Event.COMPLETE, fileLoaded);
  32                         loader.addEventListener(SecurityErrorEvent.SECURITY_ERROR, fileError);
  33                         loader.addEventListener(IOErrorEvent.IO_ERROR, fileError);
  34                         loader.load(request);
  35                 }
  36
  37                 private function fileLoaded(event:Event):void {
  38                         count=0;
  39                         xml = new XML(URLLoader(event.target).data);
  40                         for each (var inc:XML in xml.descendants('include')) {
  41                                 replaceXML(inc);
  42                                 count++;
  43                         }
  44                         if (count==0) { fireComplete(); }
  45                 }
  46
  47                 private function replaceXML(inc:XML):void {
  48                         var xmlLoader:NestedXMLLoader=new NestedXMLLoader();
  49                         var includeElement:XML=inc;
  50                         xmlLoader.addEventListener(Event.COMPLETE, function(event:Event):void {
  51                                 includeElement.parent().replace(findChildIndex(includeElement),event.target.xml);
  52                                 decreaseCount();
  53                         });
  54                         xmlLoader.load(inc.@file+"?d="+Math.random());
  55                 }
  56
  57                 private function findChildIndex(child:XML):int {
  58                         var i:uint=0;
  59                         for each (var sibling:XML in child.parent().children()) {
  60                                 if (sibling==child) return i;
  61                                 i++;
  62                         }
  63                         return -1;
  64                 }
  65
  66                 private function fileError(event:Event):void {
  67                         // just fire a complete event so we don't get an error dialogue
  68                         fireComplete();
  69                 }
  70
  71                 private function decreaseCount():void {
  72                         count--; if (count>0) return;
  73                         fireComplete();
  74                 }
  75
  76                 private function fireComplete():void {
  77                         var event:Event=new Event(Event.COMPLETE);
  78                         dispatchEvent(event);
  79                 }
  80         }
  81 }